Improvement in machines for smoothing ivory key-boards



. 'M. PRATT. Machine for Smoothinglvory Key-Boards.

No. 195,902. Patented Oct. 9, I877.

Whwas es UNITED STATES MILON PRATT, OF DEEP RIVER, CONNECTICUT, ASSIGNORTO PRATT, READ & CO., OF SAME PLACE.

IMPROVEMENT IN MACHINES FOR SMOOTHING IVORY KEY-BOARDS.

Specification forming part of Letters Patent No. 195,902, dated October9, 1877; application filed May 21, 1875.

To all whom it may concern:

Be it known that I, MILoN PRATT, of Deep River, in the county ofMiddlcsex and State of Connecticut, have invented certain Improvementsin Machines for Smoothing Ivory Key-Boards and I do hereby declare thatthe following is a full, clear, and exact description of the same,reference being had to the accompanying drawings, which form part ofthis specification. A

My invention relates to a machine for dressing and smoothing ivorykey-boards of musical instruments, in which such key-boards are carriedby a reciprocating bed, which moves them to and fro in contact with arevolving cutter-head.

The invention consists, first, in a novel mode of supporting thekey-board on the bed, whereby the ivory veneers are dressed and smoothedto a uniform thickness throughout.

The invention consists, further, in certain details of construction andarrangement of parts for the adjustment of the cutter-head to thesurface of the key-board, and the adjustment of the clamping-bars tohold the keyboard in place on the bed, and to accommodate keyboards ofdifferent widths.

In the accompanying drawings, Figure 1 is a longitudinal verticalsection of a machine constructed according to my invention. Fig. 2 is atransverse vertical section of the same. Fig. 3 is a view of the underside of the reciprocating bed.

The frame A of the machine may be of any suitable construction, and isprovided in its .upper portion with ways a, upon which slides thereciprocating bed B. On the upper side of this bed are twoclamping-bars, C D, for clamping and holding in place the key-board E.The bar C is rigidly attached to the bed 13, or, if desired, may be inone piece with said bed, and may be provided with a rib or tongue, 0,for engagement with a groove in the rear edge of the key-board, in orderto facilitate the holding of the key-board in place.

The bar D is movable, and provided with means for adjusting it laterallytoward or from the front edge of the key-board. The bed B and bars 0 Dare constructed of iron, and are planed perfectly true. The thickness ofthe bar D is greater than that of the key-board, for the purposehereinafter explained.

The key-board is prepared in the usual way by attaching to the board Ethe ivory veneers e, to form the facings for the keys, the veneers oprojecting slightly beyond the front edge of the board E, in theordinary manner.

The key-board, having been properly prepared, as above described, isplaced upon the bed B and clamped between the bars C and l) in such aposition that the rear portion of its under side rests fairly upon thebed, while the projecting edges of the veneers rest upon the upper sideof the bar I), which, being thicker than the board E, prevents the frontportion of the under side of said board from coming in contact with thesurface of the bed.

Heretofore it has been usual to place the key-board flat upon the bedwhen dressing and smoothing the upper surface of the ivory veneers, inconsequence of which, if any irregularity or inequality existed in thethickness of the board, some of the veneers would be out or scrapedthinner than others.

This disadvantage is entirely obviated in my invention. The upper sideof the board E is made perfectly smooth and level before attaching theveneers, and when the veneers are all attached to the board their undersides are necessarily all on the same level. Consequently, when thekeyboard is held upon the bed in the position described, with its frontedge supported by the overhanging edges of the veneers resting on theupper side of the bar D, and submitted to the dressing and smoothingoperation, the veneers are all cut or scraped to a uniform thickness,with their upper and lower surfaces parallel with each other.

I have thus far described the bar 1), upon which the veneers rest, asthe movable bar; but, if desired, it may be stationary, and the otherclamping-bar, C, may be movable.

In order to adjust the dressing and smoothing apparatus to the inclinedsurface of the key-board, and to regulate the adjustment to suitdifferent inclinations, resulting from different thicknesses of veneers,the shaft II, to which the cutter-head Gr is attached, is an ranged in aswinging frame, J so that it may be inclined from a vertical direction.The frame J is pivoted, preferably near the center of its lower edge, toa frame, K, and is oscillated by means of a screw, L, passing through aneye, I, attached to the frame K, and having its threaded portioneneuurine with an inter nally-threaded eye, lug, or nut. 1 attached tothe swinging frame J. lly turning the screw L in one direction or theother, the frameJ is oscillated, so as to incline the shaft II from avertical position, and thereby bring the face of the cutter-head (r to aposition exactly parallel with the surface of the veneers on thekey-board. The frame K, to which the swing;- ing' frame J is attached,is arranged to slide in vertical ways at in standards M, attached to theframe A of the machine, and is provided with a screw, P, passing througha cross-bar, N, and into atap-hole in theupperportion of the frame, bywhich means the frame may be raised and lowered in order to feed thecutter-head to and from the work. The shaft 11, carrying the cutter-head(l, is revolved rapidly by a belt passing around a pulley, 11, or in anyother suitable manner.

The bed B may be moved back and forth on the ways a by hand. or may beprovided with any suitable mechanism for reciprocating it.

\Vhen the parts are arranged, as above described, with the face of thecutter-head properly adjusted to the surface of the veneers, the

bed B is reciprocated upon the ways (4', so as to carry the key-boardback and forth under the rapidly-revolvine cutter-head, by which meansthe surface of the veneer is dressed and smoothed to a uniform thicknessthrough out.

For the lateral adjustment of the movable clamping-bar l) theftvllowing-descrilved means may be employed: A shaft, Q, is arranged inbearings (1 on the under side of the bed B, and is provided with asuitable handle, 11*, for time ing it. The shaft Qcarries two or moreworms, R, the threads of which engage with the ends of the long arms ofelbow-levers S b, pivoted to the under side of the bed 13, or with studsprojecting from said ends.

The threads of both worms may run in the same direction, and the leversmay be ar ranged to oscillate parallel with each other; but, as shownherein, the threads are arranged to run in opposite directions, and thelevers to oscillate toward and from each other, in order to facilitatethe arrangement and operation, and also to prevent end thrust on theshaft Q. The short arms of the levers are connected to plates or bars T,which work in slots t in the bed B, and to the upper sides of which themovable bar I) is attached.

\Vhen the shaft Q is turned in one direction or the other the engagementof the worms R with the levers S causes the long, arms of said levers tooscillate toward or from each other, and their short arms to move towardone side or the other of the bed 13, which movement is communicated tothe bar D, so as to draw it toward the key-board to clamp it in place,or to move it away from the key-board to allow it to be removed from thebed. As the levers move simultaneously,the motion communicated to thebar I) is uniform throughout its entire length, and the pressure of thebar against the keyboard is uniform at all points.

In order to enable the movable bar 1) to be adjusted at ditferentdistances from the stationary bar 0, to accommodate key-boards ofdilferent widths, the bar D is attached to the plates T by means ofscrews V, passing through slots at in said plates, and. provided withnuts 2, so that by loosening the nuts the bar may be moved to thedesired position, and may be held in such position by again tighteningthe nuts.

\Vhat I claim as new, and desire to secure by Letters Patent, is

1. The combination, with the bed B, of the clamping bar I), constructedas described, whereby the key-board is supported by the projecting edgesof the veneers resting upon said clamping-bar, substantially as and forthe purpose set forth.

2.. The combination, with the bed B, of the swinging frame J attached tothe verticallyadjustable frame K, and provided with means for adjustingthe cutter-head to the surface of the key-board, substantially as andfor the purpose herein described.

3. The combination of the shaft Q, worms It, levers S, plates or bars T,and movable clampingbar l), for laterally adjusting said clam] )lllg-bar, substantially as herein described.

MILON PRATT.

\Yitnesses:

lllRAM t. QMITH, SAMUEL M. SHIPMAN.

